National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
Mar Drugs. 2011;9(6):1024-1037. doi: 10.3390/md9061024. Epub 2011 Jun 10.
Dietary carotenoids, especially xanthophylls, have attracted significant attention because of their characteristic biological activities, including anti-allergic, anti-cancer, and anti-obese actions. Although no less than forty carotenoids are ingested under usual dietary habits, only six carotenoids and their metabolites have been found in human tissues, suggesting selectivity in the intestinal absorption of carotenoids. Recently, facilitated diffusion in addition to simple diffusion has been reported to mediate the intestinal absorption of carotenoids in mammals. The selective absorption of carotenoids may be caused by uptake to the intestinal epithelia by the facilitated diffusion and an unknown excretion to intestinal lumen. It is well known that β-carotene can be metabolized to vitamin A after intestinal absorption of carotenoids, but little is known about the metabolic transformation of non provitamin A xanthophylls. The enzymatic oxidation of the secondary hydroxyl group leading to keto-carotenoids would occur as a common pathway of xanthophyll metabolism in mammals. This paper reviews the absorption and metabolism of xanthophylls by introducing recent advances in this field.
膳食类胡萝卜素，特别是叶黄素，因其具有抗过敏、抗癌和抗肥胖等特性的生物活性而受到广泛关注。尽管在通常的饮食习惯下摄入了不少于四十种类胡萝卜素，但仅在人体组织中发现了六种类胡萝卜素及其代谢产物，这表明肠道对类胡萝卜素的吸收具有选择性。最近的研究表明，除了简单扩散之外，易化扩散也可以介导哺乳动物肠道对类胡萝卜素的吸收。类胡萝卜素的选择性吸收可能是通过易化扩散进入肠道上皮细胞摄取，以及未知的向肠道腔排出造成的。众所周知，β-胡萝卜素在肠道吸收类胡萝卜素后可以转化为维生素 A，但对于非维生素 A 叶黄素的代谢转化知之甚少。在哺乳动物中，次级羟基的酶促氧化会导致酮类胡萝卜素的生成，这可能是叶黄素代谢的共同途径。本文通过介绍该领域的最新进展，综述了叶黄素的吸收和代谢。
